YASKAWA SGD7S-1R9D Product Manual page 330

8.12 Additional Adjustment Functions
8.12.7 Backlash Compensation
Important
 Backlash Compensation Time Constant
You can set a time constant for a first order lag filter for the backlash compensation value
(Pn231) that is added to the position reference.
If you set Pn233 (Backlash Compensation Time Constant) to 0, the first order lag filter is dis-
abled.
Pn233
(2233
hex)
Note: Changes to the settings are applied when there is no reference pulse input and the Servomotor is stopped.
The current operation is not affected if the setting is changed during motor operation.
Related Monitoring
You can monitor the following values on the operation monitor of the SigmaWin+.
Current Backlash Compensation Value
Backlash Compensation Value Setting Limit
Compensation Operation
This section describes the operation that is performed for backlash compensation.
Note: The following figures are for when backlash compensation is applied to references in the forward direction
(Pn230 = n.0). The following monitor information is provided in the figures: target position (607A hex)
(target position in the reference coordinate system), position demand value (6062 hex) (reference position in
the reference coordinate system), and position actual value (6064 hex) (feedback position in the machine
coordinate system). The monitor information includes the feedback position in machine coordinate system
(position actual value) and other feedback information. The backlash compensation value is subtracted from
the feedback positions in the monitor information, so it is not necessary for the host controller to consider the
backlash compensation value.
8-72
• The backlash compensation value is restricted by the following formula. Backlash compensa-
tion is not performed if this condition is not met.
Denominator Pn210

Pn231 ≤
Numerator Pn20E
*
Refer to the following section for the encoder resolution.
5.14 Setting Unit Systems on page 5-42
With fully-closed loop control, substitute the number of external encoder pulses per motor rotation
for the encoder resolution in the above formula.
Example 1:
Denominator = 1, Numerator = 1, Maximum motor speed = 6,000 [min
tion = 16,777,216 (24 bits)
1/1 × 1/16 × 6,000/60 × 16,777,216 × 0.00025 = 26,214.4 [reference units]
 The backlash compensation will be limited to 26,214.4 reference units.
Example 2:
Denominator = 1, Numerator = 1, Maximum motor speed = 6,000 [min
encoder pitches (Pn20A) = 500, and Use of the JZDP-H00-000 (signal resolution: 1/256):
1/4 × 6,000/60 × (500 × 256) × 0.00025 = 800.0 [reference units]
 The backlash compensation will be limited to 800.0 reference units.
• Do not exceed the upper limit of the backlash compensation value. You can check the upper
limit on the operation monitor of the SigmaWin+.
Backlash Compensation Time Constant
Setting Range
0 to 65,535
Displayed Value
Maximum motor speed [min

60
Setting Unit Default Setting
0.01 ms 0
Setting Unit
0.1 reference units
0.1 reference units
-1 ]
 Encoder resolution*  0.00025
-1
], and Encoder resolu-
-1
], number of external
Position
When Enabled Classification
Immediately Setup